The present invention relates to an electronic apparatus, a video camera recorder or video camera/recorder for example, having a watertight housing which may be used under water, and, more particularly, to an electronic apparatus with a fail-safe structure which is capable of preventing the inner electronic equipment from being damaged by a water leakage due to degradation in watertightness of an opening portion thereof.
The housing of the conventional video camera recorder has gaps in the video tape cassette inlet, the battery receiving portion, the signal input/output terminal portion, and operation switches, and hence contaminants, moisture, and water drops are liable to enter into the interior of the housing, thereby damaging the magnetic head and the magnetic tape, and restrictions in use such as a temporary stop of use of the video camera recorder due to dew condensation, impermissible use in the rain, etc.
To overcome the problem previously described, a video camera recorder which is enhanced in watertightness by sealing gaps between adjacent parts of the housing is proposed in Japanese Patent Unexamined Publication 1-220982. Video camera recorders with waterproof housings are proposed in Japanese Patent Unexamined Publications Nos. 55-11235 and 55-124129, in which the waterproof housings are each provided with a water leakage function, a water leakage display function and a water leakage treatment function.
In Japanese Unexamined Publication No. 1-220982, the housing is separated into two chambers, each of which is separately opened. For this purpose, an inner housing is provided within the housing to cover both the video camera and the video deck. A gap is however formed between the housing and the inner housing, and thus contaminants and moisture enter into the video camera through the gap and adhere to lenses of the video camera thereby damaging the pictures recorded. Furthermore, when the housing is opened in the hot and wet air, high humidity air enters into the video camera portion. If the housing is closed in such a state, and is transported to a low temperature location such as under water, dew condensation takes place in the air within the housing, lenses of the video camera and the waterproof glasses provided to the housing cloud with the dew condensation, which may result in impossible recording. The Japanese Patent Unexamined Publication No. 55-11235 sets forth a problem as follows. In the previous proposals and existing waterproof constructions, no attention is directed to a water leakage detection technique, a detection means, a leakage display technique, and how to deal with a water leakage. Even if a sufficient waterproof construction is provided, waterproofness of the waterproof construction is not complete from points of durability and strength, taking the movable portions and the openable portions into account. Thus, the waterproof video camera recorder requires functions of detection of water leakage, display of water leakage, and water leakage treatment.
The Japanese Unexamined Publication No. 1-220982 however does not disclose such functions. Video cameras disclosed in Japanese Patent Unexamined Publications Nos. 55-11235 and 55-124129 have these functions but raise problems in functions of water leakage detection and water leakage detection treatment. More specifically, in each of the Japanese Patent Unexamined Publications Nos. 55-11235 and 55-124129, a water leakage detection unit is provided around the opening portion of the housing, and is exposed to the surface of the housing when a rear closure is opened. Thus, the water leakage detection unit is likely to malfunction because of moisture and a trace amount of water. Furthermore, the capacity of water leakage detection is liable to deteriorate due to adhesion of finger prints and contaminants such as dust. Regarding the water leakage treatment, Japanese Patent Unexamined Publication No. 55-11235 proposes that the film which watertightly coats the moisture absorbent is broken to absorb moisture; and a pump mechanism is provided so that compressed air is accumulated within the video camera by an operational force in winding the film, and, according to water leakage information, the compressed air is injected into the inside of the camera to thereby raise pressure within the camera. However, this publication does not disclose any more specific constructional features. Japanese Patent Unexamined Publications No. 55-124129 proposes an attempt such that a compressed air cartridge is provided within the housing, and, in dependence upon a signal from a water leakage detector, the compressed air is allowed to fill the inside of the housing to apply an excessively high pressure to the housing to thereby prevent the water leakage from the non watertight portion. No disclosure is made as to how to deal with water which has entered in the housing, and hence there is a possibility that the water damages the electronic equipment within the housing while the camera is being pulled up from the water after the user received a water leakage alarm.